I have no clue Emily!!! That just made me laugh! I am so sorry. I know it is probably not funny, and the last thing you want or need to deal with. But I can see my N doing the same thing and she would try and lie to about it... already. She tries to blame things on the Cats!!! For us it is her doing something to her body, glue, pens, ink, stamp pads, soap, dirt...
I hope it doesn't cause any problems... the things these kids find to mess with. ugh
OMG, I'm sorry..........but that is pretty funny! Did she just want to see where it would end up? Create a waterfall? Lordy - it seems our difficult children are doing some crazy things in these last couple of days. It must be a case of stir crazy summer madness!
To answer your question, I betcha it won't hurt you AC unit other than cause some lovely mold problems within the vent. I would change the filter tomorrow just to eliminate any moisture build up - but my guess, and it is just that - is that all would be fine.
The vent/AC is o.k. We'll get the vents cleaned, eventually. Right now as long as its o.k. I'm not going to stress about it. husband was really mad at difficult child 2, but it seems to have calmed down. (difficult child 2 also put some computer games and husband's phone down the vent.) husband even got an idea out of this mess. He put a bar of soap down difficult child 1's vent to help with the urin smell.